Hi y'all,

Car developed a bad splutter on the way home from taking photos at Croft Hillclimb wouldn't rev above 4k. That was a LONG drive home! Eventually twigged the voltage across the battery was too high (16.5V at tickover rising to 18+ volts at higher revs).

I'm pretty sure this was stopping the ECU getting the correct voltage from the pink wire resistor, cutting the coils.

Obvious rectifier issue, right?

I replaced the rectifier with a unit from ebay, a 954 blade one and spliced it in to do away with dodgy/burnt connectors. 3 yellows -> 3 yellows, 2 greens -> 1 green (earth) and 2 reds -> 1 red (+12V), black wire - NC.

Problem solved?

Nope!

Still spluttering (and frankly if I had a hammer to hand she'd have needed a new bonnet too )!

I checked the O/Ps from the stator coils - none were shorted to earth and all three read similar AC voltages - 30-50 volts depending on revs. I think that's normal-ish.

I tried a different battery and that solved it - but the voltage is still +16-17V across the battery when running and I suspect as it charges (and stops pulling the 12V line down a bit) she'll splutter again, or the battery (now a car unit) will boil.

With the headlights on the voltage drops to +14.5V - I will have them on for my MOT tomorrow - - but I also think running like this all the time would put unnecessary strain on the rectifier.

I've had a look a few other blade cars and none are running anything like that high a voltage.

Any thoughts? The 954 rectifier looked immaculate although it was 2nd hand.

Many thanks
Ali

Hi

is the rectifier getting hot when the engine is running?

if not that would indicate its not working

It is yes, certainly getting warm.
It is outputting a higher voltage than 12V as the battery as rest reads about 13V, once started that is pulled up.

which blade engine is it ?

It's a 99, 919 on carbs.

i would try one of these......

http://cgi.ebay.co.uk/Honda-CBR-900-Fireblade-92-99-Model-Regulator-Rectifier-/170354771772?cmd=ViewItem&pt=UK_Motorcycle_Parts&hash=item27a9e f873c

the 954 reg/rec may be different as that engine is fuel injected and has different electrical needs (i don't know for certain)

i had exactly the same fault on an 893 blade i used to sprint (boiled the battery etc) and it was the reg/rec

hi, i would be looking towards the regulator rather than the rectifier, or are they combined on this model?




tony

Yes the rectifier is combined with the regulator in one unit. Where I refer to the 'rectifier' read 'rectifier / regulator'.

I'm using the 954 as it was recommended by Andy Bates in a previous thread about rectifiers.

It's a much heavier duty unit. The 919 blade rectifiers have a reputation for going bang, with various symptoms. Just about any bike 3 phase regulator / rectifier will work, as long as it can handle enough current.

Where under the bonnet is it fitted ? Is it fitted to a heat sink ?

both these will reflect on how long it lasts.

Both the old & new rectifiers were directly mounded on a large aluminium plate in front of the engine. I also fitted a chip heatsink to the old unit. It lasted about 6 years!
The RR connector showed signs of charring when inspected, the main reason I cut it out.
My worry is more about boiling my battery or causing a fire as a wire burns out due to 16.5 Volts across the battery over a long time.

[Edited on 27/6/10 by alister667]

[Edited on 27/6/10 by alister667]

I put my blade ones on a heat sink on the floor in the engine bay in plenty of cool airflow, blades eat rectifiers, about the only downside to them though......

I was told once the answer to the rectifier problems on blade engines was to change to a honda super dream 250 or 400 rectifier.

Please dismiss this if its just a load of old tosh but seems most of the blade runners i know do this.

Of course it's not tosh!

You're right the superdream rectifier is a heavier duty unit, as is the 954 blade one which I've changed to. But the problem is still present!

16.5V across a battery isn't normal (is it?) and it surely is only a mater of time before the battery goes pop (isn't it?).

the reg/rec i put in the link was the same as i changed to with no more problems

also seen pc fans on top of them,though i never needed to

the black wire needs to be connected to ignition switched live supply, the later blade rectifiers are a bit more inteligent than earlier models and need to see that the power is on to start working, hook it up and it should be fine
regards
Andy

Thanks Andy!

Cheers

Ali

quote:

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Originally posted by speedystew
the reg/rec i put in the link was the same as i changed to with no more problems

also seen pc fans on top of them,though i never needed to

---

Yep, Andy was right, I ran +12V from the coils to the black wire on the rectifier and now the running voltage across the battery is 14-14.5V across the rev range.

Tried her up the road and she's fine, but of course it started raining for the first time in a couple of weeks!



Andy, many thanks again, if you make it over to Kirkistown some time, the ice creams are on me!